Film cartridge and spool therefor



f JOSEPH MIHALH JOHN W SCOTT v INVENTORS BY ATTORNEYS Filed May 23 1942J MlHALYl ETAL FILM CARTRIDGE AND SPOOL'THEREFOR Nov. 14, 1944.

Patented Nov. 14, 1944 "UNIT -ED STAT-ES PAT' E NT FFFICE,

'FILMnCARTRID'GE AND sPooL THEREFOR 1 I 'dosephMih-alyi and Johntvvscottnnoehest r;

"N."Y., assignorsto EastmanlKo'dak Company,

i-Application May 23, 1942,.hSeniabNo. 444,110 r n I pp p "'6 Claims.(019242- 71) :This invention relates T to photography and" :moreparticularly :to a photographic 'film: spool cartridge. One object ofour invention is:to'proa idenarfilm cartridge in :which i a specialmeans is :provided foricpreventing light froms entering :between'convolutionsof film wound on a spool. ,Another object of :onrqinventionis to provideza film cartridge in :whicn: the" expansion andcont-tractionyofnthe fiim :doesnotgafiect the light :seal ebetweenr the:fiim ,spoolrfianges and the .convolutionsvo'f. film iwonndthereon..Another vobjectof .onr invention is. torprovidea film. spool cartridgeewhichi is;.particulaltlyuadapted for, use with convolutionsioflflim,eliminatinguthe backing paper normally: ,used. qfitilluanother object.:of::our invention is to provide a spoolzsuitableifor nsecin such afilm--cartnidge ZStill another object of tour inventionisltoxprovidez afilmrspool' awhich ther'fla'nges .ane-sovconstnucted thatrjtheperiphcries-.101; the. flanges liercloser together i Ethan-the remainderof". the tflaln essandtto, provi-cleza: film \spooLcore :ofasuchza::nature that filrnrrwider :than the distance-between thexperripheries"of :the

..-flanges may aloex readily: drawnizontorand: unreele'd from-ourimprowedwspool.

:Inathe past, many expedients :have been used to 1 reduce, or preventflight: from entering conyvolutionsofrrfihn wound onfil-rn-fspools. Ithas 5 Coming to the ldra'wing wherein like reference :charaetersldenote'likerpartsrthroughout:

i.=E?ig.I1:is;1acperspectiveiviewiof a portionpfra .tifitlm a cartridgeconstructeldi accordance with tand-embodyingra prferredi' fonm ofour'dnventiony I ifFigJZl is: azsection" taken .on line 2'2 of Fig. 1;r=Eig. :13z-is saiiplan view of :tacblank *fromwhich t therifirm Lcore:ofIF-ig. L 1 .is'molled sup showingaone .::grid-:pattern Whichcmaybezuseid in 1 accordance with our invention;

.E'ig. 4 is ',a fragmentary detail section show- ..ing azportion :of: a.film and :film ;spoo1 constitut- :ingga slightly different embodiment ofour inven- 15':

reform ;of" our invention.

beeny-tmore T01 less common i practice to provide .mm cartridges .byminding ra film tspool with ,convolutions of backingtpa-perandfi-1m,:the backing paper protecting stile film aagainstilight ias.theconvol-utions are mound-between. two flanges. In ,someinstances-film cartridges. have been: prolvided with .backingpaperlslightly widen than; the

,distance between. the spool flanges with the edges roughened orthinnedisoaslto make intimate contactlwith film spool flangesto preventlight leak- ..age. l l

1 One of ,the chiefadifficulties has been-that even if a film is.acciuratelywcut to :-a known width the tfilmyexpandsuandtcontraetslargely iniaccondance with theemoisturecontemt -of the fi ms-so :t-hat.evern thfl ughtthetfilma itself-may closely "fit rfilm .lspool flangeswhen rmaniifactured and spooled,

the, film maynla-tersshrtnh. thusrpermitting :light rtol enterbetweenathe fiangeseand Y the edges. of the lThis may :be {particularlynoticeable taere-;-backing en isz-eliminated--. and-the? film isprovidedewithea hacking toprevent light-from massingitherethrough. y r yl .c Our improved film (cartridge is -designed i to ccompletelycove-rooms l-or-r largely eliminate flight leaks vwhichehave occurred-with 1 previous P types 60hr, invention comprises broadly providing afilm 'cartridgef:with;.an" improved form of film ospooldnwwhicheitherarigid or flexiblelfianges zrmay'rbe permanently:attachedl-toaafilm core, as tor instance by spotwelding, the film core bering;so constructed :that the distance between the "flanges may-wary inaccordance -with the width of thetfilmiorin accordance With therequirements for-spoofing. In other words -the :distance between thefilmspool flanges may auto- ;maticallyaccommodate themselves to the;partiicularwidth of the'fiim bandwwoundlon thefilm spool-V and if thefilm, through absorption of moiswture or-other-wise mayflchange inwidth, the wdistanceobetween the flanges may vary acorresponding-distance tor automatically take care of 4 this distance,

- whichrequires the film to be propelled from and rewound to a'singletspool, as in v the. copending v application. Serial-No.-430.,789,filecLFebruary 13, 1942, now. Patent No. 2,336,27 8 dated December7,?1943, for:Eilm winding apparatus, in the name of Joseph Mihalyitherfilm in passingto or from the spool may: requirethat the flangesseparate somewhat during the-Winding and rewinding. opeerations. Ourimproved spool automatically ntakes careofsuoh winding operations.

'More specifically our improved filmv cartridge --may consist of a filmI which may be attached by means of pasters-Z toa film spool core'3 towhich there are affixed the vusual flanges 4Q The film spool; core3'isof a special construction'whioh can be very readily made and which isshown inunrolled' form in Fig. 3. From this figure it will be noticedthat the "blank of which the film-spool hub 3 isformed is provided withso that it will remain one integral piece of metal.

The blank is preferably punched out of slightly springy steel so thatthe material is resilient and so that, if pressure is applied to theends of the film spool core 3 as by' pulling in opposite directions uponthe flanges 4, the length of the hub 3 may be increased since the thinmetal bands 6 of the grid-like pattern will permit such expansion.

However, if the pressure is released the thin metal bands 6 will restorethe film spool core to a normal position from which it may also becompressed by pressing the flanges 4 together. Thus, the length of thefilm core 3 is variable because of the spring construction abovedescribed.

With the blank shown-in Fig. 3 the core can be rolled up by rolling theblank 3' into a cylindrical form. If desirable, the edges 1 and 8 may befastened together as by spot welding, soldering or the like. We preferto leave the edges 9 and ID of the hub totally without perforations sothat the flanges 4 may be firmly united to these edges in any suitablemanner. We find, however, that spot welding as indicated at H is adesirable method of fastening the flanges 4 in place. I

The flanges 4 may be of a known type in which the peripheries of theflanges are provided with formations l2 extending toward each other sothat the peripheries of these flanges lie closer together than otherportions thereof. Thus, when the film I is wound on the core 3, the filmwill preferably lie inside of the area designated as A between theformings l2 and the core 3. When in this position the spring core 3 willtend to draw the flanges together and into close engagement with thelongitudinal edges M of the film s that'a close and light-tight fit isthus obtained. With the film so Wound the resiliency of the core willhold the flanges 4 tightly against the film edges !4; However, when thefilm is 'woundin a camera the flanges 4 may move away from each other asthe film passes between the formings [2 on the flanges because thedistance between the ends of the core 9 and I0 will be increased throughthe resilience of the grid portion of the core. The degree of resiliencein the core can readily be obtained by selecting'the metal-preferablysteelof such a thickness that a grid pattern can readily be punched inthe material so as to leave the metal band 6 of the proper thickness togive the desired degree of spring. We have found that for a film spooltaking film of approximately 2 in width a 'difierence'in separationbetween the flanges of around 1 3;" is usually suflicient. This distancemay be varied considerably with difierent widths or types of film.

While we find that a grid pattern leaving thin metal strips 6 runningsubstantially transversely of the axis of the film core is verydesirable since We would like to point out that the scale of the filmspools shown in the drawing is somewhat exaggerated, particularly as tothe thickness of the metal and the degree of embossing shown in theflanges 4, so that our invention may more readily be illustrated.Actually the film spool hubs can conveniently be made of metal around.015" thick and if the spool flanges 4 are to be of the rigid type'metalof the same thickness may be used. However, if spring steel is to beused for the flanges this thickness can be reduced to say .008". Thesefigures are given purely by. way of example because it is a littledifiicult to visualize the spring core 3 and to realize how a delicatepressure can cause the .type of spool supporting bearings, one flangefor instance may be provided with a key slot 24 and the oppositeflange'may be provided with a round bearing 25,- such bearings beingfamiliar to those skilled in the art.

In attaching the film I to the core 3, we propose to use pasters 2 asshown in Fig. 1, one paster being spaced on each side of the portion ofthe core 3 bearing the punched-out areas. In Fig. 1 the inner edge ofthe film 26 may be spaced a short distance from the core 3. However, ifthe film cartridge is to be used for unwinding and winding film as shownbroadly in the above-referred to Mihalyi application, it is usually moreconvenient to have the inner 'end 26 of the film lie close to orincontact with the core 3 as indicated in Fig. 4. The same type ofpasters 2 may be used if desired.

With the film cartridge including our improved spool, the liability ofaccidental exposure of the film to light is greatly minimized or maybeentirely eliminated since the flanges 4 always tend to remain in closecontact with the edges I4 of the film. This is due to the fact that thecore 3 is so built that its normal position of rest will hold theflanges spaced the same distance as the width of the film or slightlyless than the minimum width of the film; Thus, with most film cartridgesthe core 3 applies a slight inward pressure to the convolutions 'of filmI wound between the flanges. This pressure is very slight and the filmcan be withdrawn from between the flanges by permitting'the flanges tospring apart as the film passes over the embossings l2.

.Our spool is economical to construct because it may be'made of theusual three pieces of metal which are frequently employed in known typesof film cartridges and because the core may be embodied in a singlepiece of metal which may be blanked out and rolled up with the samemachinery now usedto manufacture the solid core film spools except forthe perforating dies used to provide the resilient grid pattern.

What we claim as new and desire to be secured by Letters Patent of theUnited'States is:

1. In a film cartridge, the combination with a strip of film of knownwidth, of a spool on which said film may be wound comprising a one-piececore, flanges attached to the core, inwardly turned peripheries on saidflanges whereby the peripheries of the two flanges lie closer togetherthan other portions of said flanges, means included in the film core forholding convolutions separating the spool flanges due to flexing of thefilm spool core.

2. A spool for film cartridges including a spool with convolutions offilm of known width wound thereon and comprising a tubular coreconstructed of a resilient metal and having an imperforate portion andaperforate portion, flanges attached to the ends of the core, theimperforate portion of the core being substantially incompressible andinexpansible by the application of ordinary manual force, the perforateportion of the core consisting of a plurality of narrow interconnectingbands of the resilient core metal forming a resilient area tending tohold the flanges at a predetermined spacing and flexing when the flangesare moved relative to each other.

3. A spool for film cartridges including a spool with convolutions offilm of known width wound thereon and comprising a tubular coreconstructed of a resilient metal and having imperforate ends and aperforate section between the ends, flanges affixed to the imperforateends and-normally held at a predetermined spacing by the core, saidperforate portion comprising a plurality of narrow connected bandspositioned to provide resilience in the core whereby a film wider thanthe predetermined spacing of said flanges may be wound therebetween, andsaid flanges may be resiliently held against said convolutions of film.

4. A spool for film cartridges including a spool with convolutions offilm of known width wound thereon and comprising a tubular coreconstructed of a resilient metal and having an imperforate portion and aperforate portion, flanges attached to the ends of the core, theimperforate portion of the core being substantially incompressible andinexpansible by the application of ordinary manual force, the perforatepor- I tion of the core consisting of a plurality of narrowinterconnecting bands extending in a general direction transverse to theaxis of the core whereby the resilient perforate metal of-the core maybe flexed while the imperforate metal of the core remains substantiallyrigid.

5. A spool for film cartridges including a spool with convolutions offilm of known width wound thereon and comprising a tubular coreconstructed of a resilient metal and having an imperforate portion and aperforate portion, flanges attached to the ends of the core, theimperforate portion of the core being substantially incompressible andinexpansible by the application of ordinary manual force, the perforateportion of the core consisting of a plurality of narrow interconnectingbands extending in a general direction transverse to the axis of thecore and constituting a lattice pattern in which the said narrowconnecting bands are each of much greater length than width transverselyof the core facilitating flexure of the core in a directionsubstantially parallel with the length of the core.

6. A spool for film cartridges including a strip of film of known width,said spool comprising a one-piece core of resilient metal, flangesattached to the core having inwardly turned peripheries on said flangeswhich lie closer together than other portions of the flanges, meansincluded in the film core adapted to hold convolutions of film betweenthe inwardly turned peripheries of the flanges, said means comprising aflexible portion formed integrally in the core and of a flexibility topermit the withdrawal of film from the convolutions carried by the corethrough separating the spool flanges due to flexing the film spool core.

JOHN W. SCOTT. JOSEPH MIHALYI.

